電磁鐵的發明

1822年，法國物理學家阿拉戈和呂薩克發現，當電流通過其中有鐵塊的繞線時，它能使繞線中的鐵塊磁化。這實際上是中山電磁鐵原理(li)的最初發(fa)現。1823年，斯特金也做了一次類似的實驗：他(ta)在一根并非是(shi)磁(ci)鐵(tie)(tie)棒的U型鐵(tie)(tie)棒上(shang)繞(rao)了18圈(quan)(quan)銅(tong)裸線，當銅(tong)線與伏打(da)電(dian)(dian)池接通時，繞(rao)在U型鐵(tie)(tie)棒上(shang)的銅(tong)線圈(quan)(quan)即(ji)產生了密(mi)集(ji)的磁(ci)場，這(zhe)樣就使U型鐵(tie)(tie)棒變成了一塊(kuai)“電(dian)(dian)磁(ci)鐵(tie)(tie)”。這(zhe)種電(dian)(dian)磁(ci)鐵(tie)(tie)上(shang)的磁(ci)能要比永磁(ci)能大放(fang)多倍(bei)，它能吸(xi)起(qi)比它重20倍(bei)的鐵(tie)(tie)塊(kuai)，而當電(dian)(dian)源切斷后，U型鐵(tie)(tie)棒就什么鐵(tie)(tie)塊(kuai)也吸(xi)不住，重新成為(wei)一根普通的鐵(tie)(tie)棒。

斯特金的電磁(ci)鐵(tie)發明(ming)，使人們看到了把電能(neng)(neng)轉化為磁(ci)能(neng)(neng)的光明(ming)前(qian)景，這一(yi)發明(ming)很快在英(ying)國(guo)(guo)、美國(guo)(guo)以(yi)及西(xi)歐一(yi)些沿海(hai)國(guo)(guo)家傳播開來。

1829年(nian)，美國(guo)電學家亨利對斯特金電磁(ci)(ci)鐵(tie)裝置進行(xing)了(le)(le)一(yi)(yi)些革新，絕緣(yuan)導(dao)(dao)線(xian)代替裸銅導(dao)(dao)線(xian)，因此不必擔心被銅導(dao)(dao)線(xian)過分靠近而短路(lu)。由于導(dao)(dao)線(xian)有了(le)(le)絕緣(yuan)層(ceng)，就(jiu)可以將(jiang)它們一(yi)(yi)圈(quan)圈(quan)地(di)緊緊地(di)繞在一(yi)(yi)起，由于線(xian)圈(quan)越(yue)密集(ji)，產生的(de)磁(ci)(ci)場就(jiu)越(yue)強，這(zhe)樣就(jiu)大大提高了(le)(le)把電能(neng)轉化為磁(ci)(ci)能(neng)的(de)能(neng)力。到了(le)(le)1831年(nian)，亨利試制(zhi)出(chu)了(le)(le)一(yi)(yi)塊更新的(de)電磁(ci)(ci)鐵(tie)，雖然它的(de)體積并不大，但它能(neng)吸(xi)起1噸重的(de)鐵(tie)塊。

電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)內部帶有(you)(you)(you)鐵(tie)(tie)心(xin)的、利(li)用通(tong)有(you)(you)(you)電(dian)(dian)流的線(xian)圈(quan)使其像磁(ci)(ci)(ci)(ci)鐵(tie)(tie)一樣(yang)具有(you)(you)(you)磁(ci)(ci)(ci)(ci)性(xing)的裝置(zhi)叫做(zuo)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)，通(tong)常(chang)制(zhi)成條形或蹄(ti)形。鐵(tie)(tie)心(xin)要用容易(yi)磁(ci)(ci)(ci)(ci)化，又(you)容易(yi)消(xiao)(xiao)失磁(ci)(ci)(ci)(ci)性(xing)的軟鐵(tie)(tie)或硅(gui)鋼來(lai)制(zhi)做(zuo)。這樣(yang)的電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)在通(tong)電(dian)(dian)時有(you)(you)(you)磁(ci)(ci)(ci)(ci)性(xing)，斷電(dian)(dian)后就隨(sui)之消(xiao)(xiao)失。 電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有(you)(you)(you)許多優(you)點：電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)磁(ci)(ci)(ci)(ci)性(xing)的有(you)(you)(you)無，可以用通(tong)、斷電(dian)(dian)流控制(zhi)。磁(ci)(ci)(ci)(ci)性(xing)的大小可以用電(dian)(dian)流的強(qiang)弱或線(xian)圈(quan)的匝數來(lai)控制(zhi)。

電磁鐵的主要特點

1、采(cai)用(yong)全密封(feng)結構(gou)，防潮性能好(hao)。

2、經計算機優(you)化設計，結構合(he)理、自重(zhong)輕(qing)、吸(xi)力大(da)、能耗低。

3、勵磁線圈經特(te)別工藝處理，提(ti)高了線圈的電器和機械(xie)性能，絕緣(yuan)資料熱等級(ji)到達C級(ji)，運用壽命長。

4、普通(tong)型(xing)電磁鐵的(de)額定(ding)通(tong)電持續率(lv)由曩(nang)昔的(de)50%提高到60%，提高了電磁鐵的(de)運(yun)用功率(lv)。

5、超(chao)高溫型電磁(ci)鐵(tie)采用獨特隔熱方(fang)式，其間被吸物溫度有曩昔(xi)的(de)600℃提高700℃，擴(kuo)大了電磁(ci)鐵(tie)的(de)適用范圍。

6、裝(zhuang)置、運轉(zhuan)、保護(hu)簡(jian)潔。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)磁(ci)(ci)能(neng)變換(huan)為機械能(neng)以(yi)實現(xian)吸(xi)合作功(gong)的(de)(de)一種電(dian)(dian)(dian)(dian)器。通(tong)常由軟(ruan)磁(ci)(ci)材料制(zhi)成的(de)(de)鐵(tie)(tie)(tie)(tie)(tie)心、銜鐵(tie)(tie)(tie)(tie)(tie)和(he)(he)勵(li)磁(ci)(ci)繞(rao)組(zu)組(zu)成。當(dang)勵(li)磁(ci)(ci)繞(rao)組(zu)通(tong)電(dian)(dian)(dian)(dian)時(shi)，繞(rao)組(zu)周圍產(chan)生磁(ci)(ci)場(chang)，鐵(tie)(tie)(tie)(tie)(tie)心磁(ci)(ci)化，并產(chan)生電(dian)(dian)(dian)(dian)磁(ci)(ci)吸(xi)力(li)吸(xi)引銜鐵(tie)(tie)(tie)(tie)(tie)，使(shi)之(zhi)運動作功(gong)。電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)主要用(yong)于操動、牽引機械裝置，以(yi)達(da)到(dao)預期的(de)(de)目的(de)(de)。工(gong)業上常用(yong)的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)有制(zhi)動電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)、牽引電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)、起(qi)重電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)和(he)(he)閥用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)等。此(ci)外，屬于電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)類的(de)(de)還有用(yong)以(yi)傳遞或隔斷兩軸間的(de)(de)機械聯(lian)系的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)聯(lian)軸器;用(yong)在(zai)機床工(gong)作臺上以(yi)吸(xi)牢(lao)磁(ci)(ci)性材料工(gong)件的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)吸(xi)盤;供高能(neng)物理、核聚變研究、磁(ci)(ci)流體發電(dian)(dian)(dian)(dian)和(he)(he)高速懸浮列車等方(fang)面使(shi)用(yong)的(de)(de)、能(neng)產(chan)生高達(da)數十(shi)特（斯拉）的(de)(de)磁(ci)(ci)通(tong)密度(du)而幾乎不消耗繞(rao)組(zu)功(gong)率的(de)(de)超導電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)等。

起重電磁鐵

用來吊(diao)運和(he)裝(zhuang)卸鐵(tie)(tie)磁(ci)性物體(ti)的電(dian)(dian)磁(ci)鐵(tie)(tie)。工(gong)業(ye)上常用以吊(diao)運或(huo)裝(zhuang)卸鐵(tie)(tie)礦石、鐵(tie)(tie)砂、廢鋼(gang)鐵(tie)(tie)、鋼(gang)錠、鋼(gang)軌以及各種鋼(gang)材和(he)鋼(gang)質工(gong)件。起重電(dian)(dian)磁(ci)鐵(tie)(tie)通常做成圓盤形或(huo)矩形，并帶(dai)有內磁(ci)極(ji)和(he)外磁(ci)極(ji)。當(dang)(dang)勵(li)磁(ci)繞組通電(dian)(dian)后，內外磁(ci)極(ji)均被磁(ci)化，吸(xi)引鋼(gang)質材料或(huo)工(gong)件（相當(dang)(dang)于一般電(dian)(dian)磁(ci)鐵(tie)(tie)中的銜鐵(tie)(tie)），形成一個閉合的磁(ci)路。為(wei)保(bao)護(hu)勵(li)磁(ci)繞組，使之不(bu)因磁(ci)極(ji)與被吸(xi)引物體(ti)間(jian)的機(ji)械撞擊所損傷，起重電(dian)(dian)磁(ci)鐵(tie)(tie)通常采用甲殼式結構，并且采用直流(liu)勵(li)磁(ci)。

牽引電磁鐵

供(gong)牽引(yin)(yin)(yin)和(he)(he)推斥機(ji)械裝(zhuang)置用(yong)的(de)(de)(de)一種電(dian)磁(ci)(ci)鐵(tie)。主(zhu)要用(yong)于各(ge)種自(zi)動(dong)設備中，以(yi)實現遠距離控制(zhi)(zhi)。為了能夠在長行(xing)程(cheng)下(xia)獲得(de)較大(da)的(de)(de)(de)電(dian)磁(ci)(ci)吸(xi)力，牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)一般采用(yong)吸(xi)引(yin)(yin)(yin)特性比較平坦的(de)(de)(de)甲殼(ke)式結構。其內部(bu)裝(zhuang)有(you)鐵(tie)心(xin)、銜(xian)鐵(tie)和(he)(he)勵磁(ci)(ci)線圈(quan)。使用(yong)時，將(jiang)鐵(tie)心(xin)固定在機(ji)械裝(zhuang)置的(de)(de)(de)靜(jing)止部(bu)件上(shang)，銜(xian)鐵(tie)則(ze)連接在牽引(yin)(yin)(yin)桿上(shang)。當勵磁(ci)(ci)繞組通電(dian)后(hou)，鐵(tie)心(xin)被(bei)磁(ci)(ci)化，產生電(dian)磁(ci)(ci)吸(xi)力吸(xi)引(yin)(yin)(yin)銜(xian)鐵(tie)，后(hou)者則(ze)通過牽引(yin)(yin)(yin)桿來操縱所控制(zhi)(zhi)的(de)(de)(de)機(ji)械裝(zhuang)置的(de)(de)(de)機(ji)構。為了適應(ying)不同控制(zhi)(zhi)對(dui)象的(de)(de)(de)需要，牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)有(you)拉動(dong)式和(he)(he)推動(dong)式兩種，但都不具備復位(wei)裝(zhuang)置。牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)的(de)(de)(de)主(zhu)要技(ji)術(shu)指標為一定行(xing)程(cheng)下(xia)的(de)(de)(de)電(dian)磁(ci)(ci)吸(xi)力、操作頻率和(he)(he)壽(shou)命。

制動電磁鐵

作(zuo)(zuo)(zuo)(zuo)機(ji)(ji)械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)用(yong)(yong)(yong)(yong)的(de)(de)一種電(dian)磁(ci)鐵(tie)。主(zhu)要(yao)用(yong)(yong)(yong)(yong)于電(dian)力驅動(dong)(dong)(dong)(dong)(dong)裝(zhuang)置(zhi)和起重運(yun)輸設(she)備中，并與(yu)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配(pei)(pei)合使(shi)(shi)用(yong)(yong)(yong)(yong)，使(shi)(shi)電(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)準(zhun)確(que)停(ting)車和懸吊著(zhu)的(de)(de)重物不致墜(zhui)落。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)按(an)銜鐵(tie)行(xing)(xing)(xing)(xing)程分(fen)為(wei)長(chang)行(xing)(xing)(xing)(xing)程和短行(xing)(xing)(xing)(xing)程兩類;按(an)勵(li)磁(ci)方(fang)式分(fen)為(wei)直流和交(jiao)流、并勵(li)和串勵(li)以(yi)及單相和三(san)相等種類。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)的(de)(de)工作(zuo)(zuo)(zuo)(zuo)原理是(shi)(shi)：當(dang)電(dian)磁(ci)鐵(tie)的(de)(de)繞組(zu)通(tong)(tong)電(dian)后，銜鐵(tie)被吸向鐵(tie)心，并通(tong)(tong)過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中的(de)(de)停(ting)檔壓(ya)迫制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)，使(shi)(shi)之(zhi)(zhi)移動(dong)(dong)(dong)(dong)(dong)，從而(er)(er)迫使(shi)(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松閘。切斷線圈電(dian)源后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)在彈簧(huang)作(zuo)(zuo)(zuo)(zuo)用(yong)(yong)(yong)(yong)下使(shi)(shi)銜鐵(tie)脫離磁(ci)軛，而(er)(er)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則將(jiang)機(ji)(ji)構剎住。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)的(de)(de)主(zhu)要(yao)技術參數是(shi)(shi)行(xing)(xing)(xing)(xing)程、一定行(xing)(xing)(xing)(xing)程下的(de)(de)電(dian)磁(ci)吸力、操(cao)作(zuo)(zuo)(zuo)(zuo)頻(pin)(pin)率(lv)(lv)(lv)和通(tong)(tong)電(dian)持(chi)續率(lv)(lv)(lv)。操(cao)作(zuo)(zuo)(zuo)(zuo)頻(pin)(pin)率(lv)(lv)(lv)是(shi)(shi)指(zhi)(zhi)每小時(shi)操(cao)作(zuo)(zuo)(zuo)(zuo)的(de)(de)次數;通(tong)(tong)電(dian)持(chi)續率(lv)(lv)(lv)是(shi)(shi)指(zhi)(zhi)每次通(tong)(tong)電(dian)時(shi)間與(yu)每次通(tong)(tong)電(dian)及不通(tong)(tong)電(dian)時(shi)間之(zhi)(zhi)和的(de)(de)百分(fen)比。使(shi)(shi)用(yong)(yong)(yong)(yong)中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)與(yu)瓦式制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配(pei)(pei)合時(shi)用(yong)(yong)(yong)(yong)短行(xing)(xing)(xing)(xing)程類;與(yu)皮帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配(pei)(pei)合時(shi)用(yong)(yong)(yong)(yong)長(chang)行(xing)(xing)(xing)(xing)程類。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)通(tong)(tong)過(guo)液壓(ya)方(fang)式將(jiang)電(dian)磁(ci)力傳遞(di)給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)構的(de)(de)稱液壓(ya)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)磁(ci)鐵(tie)。

閥用電磁鐵

供(gong)遠距離操作各種(zhong)液壓、氣(qi)動系統閥(fa)門(men)的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用(yong)于(yu)各種(zhong)金屬切(qie)削機床中(zhong)(zhong)。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設復位裝置，而由閥(fa)體(ti)(ti)中(zhong)(zhong)的(de)彈(dan)簧(huang)使(shi)之(zhi)復位。當電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)勵(li)磁(ci)(ci)(ci)繞(rao)組(zu)通過(guo)電(dian)(dian)流時，電(dian)(dian)磁(ci)(ci)(ci)吸力即克服彈(dan)簧(huang)阻力，使(shi)閥(fa)體(ti)(ti)的(de)推(tui)桿移動，將閥(fa)門(men)開啟;當勵(li)磁(ci)(ci)(ci)繞(rao)組(zu)斷電(dian)(dian)后，在(zai)復位彈(dan)簧(huang)作用(yong)下，閥(fa)體(ti)(ti)推(tui)桿便推(tui)動銜鐵(tie)(tie)，使(shi)其(qi)(qi)移動額定行程(cheng)處，閥(fa)門(men)關閉。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分為濕(shi)式(shi)和(he)干(gan)式(shi)兩(liang)種(zhong)。濕(shi)式(shi)閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)銜鐵(tie)(tie)在(zai)液壓油(you)中(zhong)(zhong)工作，由于(yu)油(you)的(de)冷卻作用(yong)，使(shi)其(qi)(qi)與具有相同吸力的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相比，有較小的(de)尺寸。

電磁鐵的應用

門(men)(men)禁：為什(shen)么門(men)(men)禁可(ke)以在沒刷(shua)卡時把門(men)(men)牢(lao)牢(lao)的“抓住(zhu)”？原來(lai)單元門(men)(men)是由鋼材料做(zuo)成的，那個金屬體在通電(dian)時可(ke)以產(chan)生強大的磁場，產(chan)生的磁力能(neng)把門(men)(men)牢(lao)牢(lao)的吸住(zhu)，而刷(shua)卡的瞬(shun)間，切斷電(dian)流，金屬體失去磁性，我們就可(ke)以打開(kai)門(men)(men)了。那個金屬體其實是一塊電(dian)磁鐵。

電(dian)磁(ci)(ci)起重機：最直接的(de)應用之一是電(dian)磁(ci)(ci)起重機。電(dian)磁(ci)(ci)鐵安裝在吊車上，通電(dian)后吸起大(da)量(liang)鋼鐵，移動到(dao)另一個位置后切斷電(dian)流，鋼鐵被放下(xia)，免去了(le)打捆的(de)麻煩。大(da)型電(dian)磁(ci)(ci)起重機一次可以吊起幾噸鋼材。

在電動機(ji)、發電機(ji)、電鈴(ling)和電磁(ci)繼電器里(li)也用到電磁(ci)鐵(tie)。全自動洗衣(yi)機(ji)的進水(shui)、排水(shui)閥(fa)門(men)，衛(wei)生(sheng)間里(li)感(gan)應(ying)式沖水(shui)器的閥(fa)門(men)，也都是由電磁(ci)鐵(tie)控(kong)制的。

電(dian)磁(ci)(ci)鐵的另一個應用是產(chan)生強磁(ci)(ci)場。現代(dai)技術中很多(duo)地(di)方需要的強磁(ci)(ci)場都由電(dian)磁(ci)(ci)鐵提供，如大型電(dian)動(dong)機、發(fa)電(dian)機、磁(ci)(ci)療(liao)設備等(deng)。